Textile materials having durable antistatic properties

ABSTRACT

A TEXTILE MATERIAL HAVING DURABLE ANTISTATIC PROPERTIES, SAID MATERIAL COMPRISING ORGANIC TEXTILE FIBERS AND A MINOR AMOUNT OF ELECTRICALLY CONDUCTIVE FIBERS, EACH OF SAID ELECTRICALLY CONDUCTIVE FIBERS COMPROSING A SUBSTRATE OF ORGANIC SYNTHETIC FIBER AND A METALLIC COATING CHEMICALLY DEPOSITED THEREON, SAID ELECTRICALLY CONDUCTIVE FIBER POSSESSING THE FUNCTIONAL PROPERTIES OF TEXTILE FIBERS.

United States Patent US. Cl. 117-217 6 Claims ABSTRACT OF THE DISCLOSUREA textile material having durable antistatic properties, said materialcomprising organic textile fibers and a minor amount of electricallyconductive fibers, each of said electrically conductive fiberscomprising a substrate of organic synthetic fiber and a metallic coatingchemically deposited thereon, said electrically conductive fiberpossessing the functional properties of textile fibers.

This invention relates to textile materials having durable antistaticproperties.

Organic textile fibers have, in general, the shortcoming that theybecome charged with static electricity upon being rubbed especially atlow humidity. This tendency is particularly great in the case, forexample, of the synthetic fibers such as polyamide, polyester, acrylicand polyolefin fibers, as well as semi-synthetic fibers such as acetateand triacetate fibers. This electrification phenomenon becomes also aproblem during the manufacture of textile products.

As one means of solving this problem, it has been suggested toincorporate a small amount of metallic fibers in the textile material(US. Pat. 3,288,175). However, since the usual textile fibers differessentially in nature from the metallic fibers, there were problems inthe mixing and processing steps as well as the hand of the resultingproduct. Furthermore, the manufacture of metallic fibers in fine denieris not simple, and this process frequently results in the cost of thefiber becoming high.

It was found that if the thickness of the metallic coating is adjustedto 0.01-1.5 microns in chemically plating a metallic coating on anorganic synthetic fiber made of an acrylic polymer consistingessentially of at least 80 mol percent acrylonitrile to render itelectrically conductive, the resulting product retains its functionalproperties as a textile fibers; and that the incorporation of about0.01-2%, based on the weight of said organic textile fibers, of suchelectrically conductive fibers in the usual organic textile fibers madeit possible to control the undesirable electrifying tendency of thelatter very readily and lastingly.

The term fiber, as used herein and the appended claims, unless otherwisenoted, comprehends those of staple fiber form as well as those ofcontinuous filament form.

As the organic synthetic fibers to be used as the substrate of theelectrically conductive fibers, particularly to be preferred from thestandpoint of the ease of application of the metallic coating and theirability to adhere metals are those of acrylic polymer in which thecontent of acrylonitrile is at least 80 mol percent and those ofpolyester whose content of ethylene terephthalate is at least 80 molpercent, but the fibers of the other synthetic polymers such, forexample, as polyamide, polyvinyl acetal, polyolefin, polyurea andpolyimide can also be used. It is also possible to use a fiber in whichan undercoat layer comprising an organic polymeric material is formed onthe substrate fiber in order to enhance its adhesion to a metal coating.The substrate fiber can have a textile denier of about 1-50 deniers.

3,666,550 Patented May 30, 1972 The metallic coating can be applied tothe substrate by the method which per se is known for chemical platingof organic polymeric materials, optionally followed by electroplating.Chemical plating can be carried out on substrate fibers ofmultifilament, monofilament or staple form.

As examples of metals suitable for chemical plating on the substrate,there are nickel, copper, cobalt, chromium, zinc and tin, but from thestandpoint of ease of plating and economy nickel and copper are ofadvantage.

In carrying out the chemical plating of shaped articles such as castarticles of organic polymeric materials, the general practice is toperform such pretreatments as mechanical roughening, degreasing,etching, sensitizing and activation of the surface. The step ofmechanically roughening the surface is performed with a view of forminga rough surface suitable for performing the metallic plating, but in thecase of a substrate of fiber form, it was found that this step was notparticularly necessary, since the surface of the fiber is roughened to asuitable extent to be already convenient for carrying out the metallicplating operation.

The degreasing step whose purpose is to clean the surface of thesubstrate fiber and remove such soiling as oils and fats, can be readilycarried out by means of the usual neutral or weakly alkaline detergents.The oiling agents which have been adhered to the fiber during itsmanufacture can usually be removed fully by a simple degreasingtreatment, and it is also possible, depending upon the substrate, toproceed to the next step Without performing the water-washing anddegreasing treatment.

The etching step is for exposing a hydrophilic surface by swelling thesurface of the substrate and chemically corroding it, which is anespecially important step in ensuring the adhesion of the metal to thesubstrate.

As the etchant that is especially effective with the acrylic fibers,included are the acid etchants such as chromic acidsulfuric acid,potassium bicromate-sulfuric acid, potassium bichromate-phosphoric acid,nitric acid, and chromic acidnitric acid, and the alkaline etchants suchas caustic soda. and caustic potash. While the acrylic fibers areessentially superior in their resistance to chemical attack andresistance to heat, it is still necessary to exercise care to ensureagainst their degradation since a fine fiber is to be used as thesubstrate. Hence, it is important to choose conditions which are optimumfor obtaining satisfactory adhesiveness between the substrate and thecoating. Generally speaking, the fiber need not be subjected to a harshetching; an etching treatment for a short period of time under mildconditions should be sufficient. For example, when the chromicacid-sulfuric acid type of etchant [50-l00 g./l. of chromic anhydrideplus 100-300 g./l. of concentrated sulfuric acid is used, the end can befully achieved by a treatment for 5 seconds to 5 minutes at roomtemperature.

The substrate fiber which has received the etching treatment is usuallysubmitted to a sensitizing and activation pretreatment before beingchemically plated.

The sensitizing step consists in causing the adsorption and orientationof a reducing agent on the surface of the substrate which has beenrendered hydrophilic in the etching step, and as the sensitizing bath,an acid or alkaline bath of a stannous compound, such as stannouschloride, titanium trichloride or aluminum chloride can be used, butfrom the standpoint of sensitizing effect and economy, a stannouschloride-hydrochloric acid type sensitizer, e.g. a bath consisting of5180 g./l. of stannous chloride and 1-180 cc./l. of concentratedhydrochloric acid (35%), is particularly convenient, the end being fullyachieved by a treatment of 3 seconds to 3 minutes at room temperature to50 C.

The activation step consists in depositing on the surface of thesubstrate a noble metal such as palladium, platinum, gold and rhodium,which is active as catalysts in carrying out the chemical metal plating.While any of the known activators is effective, especially convenient isthe palladium chloride-hydrochloric acid type activator (e.g. a bathconsisting of 0.025-5 g./ l. of palladium chloride and 0.25- 25 g./l. ofconcentrated hydrochloric acid (35%)), the end being fully achieved by atreatment of 3 seconds-6 minutes at room temperature to 60 C.

Next, the chemical metal plating is carried out on the surface of thefiber. As previously stated, particularly preferred is either a chemicalnickel plating or chemical copper plating. As the composition of thechemical nickel plating bath, several types can be mentioned, such assoluble nickel salt-hypophosphite, soluble nickel salt-boron nitrogencompound, and soluble nickel salt-urea. While basically any of thesecompositions can be used with full satisfaction, convenient is the bathwhose composition is of the soluble nickel salt-phosphite type, andparticularly preferred is that of this type which is acidic. Anexcellent electrically conductive fiber can be obtained With a veryshort period of treatment by the use a relatively high plating bathtemperature. For example, when an acidic plating bath consistingpredominantly of 20 g./l. of nickel sulfate, 24 g./l. of sodiumhypophosphite and 27 g./l. of lactic acid and whose pH has been adjustedto 5.6 is used, satisfactory treatment is obtained with a plating bathtemperature of 60-98 C. and a treatment time of 10 seconds-9 minutes.Particularly, if the treatment is carried out at a plating bathtemperature of 80-90 C., a fiber excelling in electric conductivity canbe obtained satisfactorily even with a treatment time of less than oneminute. Since, as hereinbefore described, the chemical nickel platingcan be carried out under treatment conditions requiring a very shortperiod of time, it is especial: ly convenient to use it in thecontinuous chemical plating of filaments.

As the bath composition for chemical copper plating, combinationsconsisting of soluble copper salts and the various reducing agents canbe mentioned, but especially suitable is that of the soluble coppersalt-formalin type. Chemical copper plating generally has theshortcomings that its bath life is short and the deposition speed isslow, but it is featured in that even though the plate thickness isquite thin a very uniform durable electrically conductive fiber can beobtained whose conductivity is superior, adhesion is good and, inaddition, pliability and flexibility are also excellent. When, as thesoluble copper salt-formalin type chemical plating bath, for example,one consisting of 30 g./l. of copper sulfate, 100 g./l. of Rochelle saltand 50 ml./l. of formaline (37%) as principal components and adjusted topH 11-12 with sodium hydroxide is used, a treatment for 3-10 minutes atroom temperature is sufiicient to yield an excellent electricallyconductive fiber.

It was found surprisingly that a good metallic coating could be formedon the substrate even when the hereinbefore described etching step wasomitted when an acrylic fiber was used as the substrate. It was foundmoreover that the adhesiveness of the metallic coating to the substratewas far superior to that in the case where the other fibers were used.While this has not been fully clarified as yet, it is believed that itis ascribable to the inherent surface configuration of the acrylic fiber(the acrylic fiber has chiefly a dog-bonelike cross-section and thesectional configuration in the axial direction of the fiber variesgreatly in an irregular manner) and the affinity between the nitrilegroup in the substrate and the metal (chelating effect). 1

. The metallic coating which has been chemically plated on the substratefiber can, if desired, be increased in its thickness by furtherdeposition of metal thereon by electroplating. The metal to beelectroplated may be one which is the same as that which was chemicalplated or one dilfering therefrom.

The thickness of the metallic coating formed on the substrate fiber mustbe controlled so as to ensure that the product retains the functionalproperties of textile fibers. A metallic coating of excessive thicknessresults in a prodnot having poor pliability and flexibility and is alsounnecessary from the standpoint of conductivity. The upper limit of theaverage thickness of the metallic coating will depend upon the class anddenier of the substrate fiber, the class of metal, and the use to whichthe final product is to be put, but in most cases it should not exceed1.5 microns. On the other hand, the lower limit of the average thicknessof the metallic coating will suflice with one which will render thefiber conductive, i.e. the thickness which will ensure a volume inherentresistivity of l0- l0. fl-cm. It was found that there were frequentlydiscontinuities in the metallic coating whose average thickness was lessthan 0.01 micron and, as a result, that the coated product frequentlydid not have a satisfactory conductivity. Hence, it is preferable tocontrol the average thickness of the metallic coating to within therange of 0.01 to 1.5 microns, and particularly 0.1 to 0.5 micron.

A top coating of an organic polymeric material can be applied to theelectrically conductive fiber to protect the metallic coating from beingoxidized and corroded and peeling off from the substrate. However, thistop coating must be one that does not make the electric resistance ofthe fiber greater than about 2000M0/cm. As the organic polymericmaterial to be applied, preferred are the synthetic rubber type polymerswhich excel in their adhesiveness to metal and the water-repellentsilicon resin type polymers, but others can also be used.

The textile materials having durable antisatic properties in accordancewith this invention comprise the usual organic textile fiber and a minoramount of the hereinbefore described electrically conductive fiber. Theaforesaid electrically conductive fiber can be present in the textilematerial and product according to the invention in a proportion of 0.01%to 10% by weight. Thus, 0.01% to 2% and preferably 0.05% to 2% by weightbased on the organic textile fiber may be employed. With a proportion ofthe electrically conductive fiber of less than 0.01% by weight itfrequently happens that a pronounced antistatic effect cannot beachieved, whereas with a proportion of the eelctrically conductive fiberof 2% to 10% by weight, the rate of improvement in the antistatic elfectin proportion to the increase in the electrically conductive fiberhardly increases. The use of the electrically conductive fiber in excessof about 10% by weight is unnecessary. In fact, little is to be gainedin employing over 2% conductive fiber.

The electrically conductive fiber can be combined with the ordinaryorganic textile fibers by an optional means such as mix spinning, mixtwisting, mix weaving and mix knitting. And in this case, it is notnecessarily required that the former is evenly distributed in thelatter. For example, a textile fabric according to this invention can beWoven by distributing one end of woof yarn containing the electricallyconductive fiber at an interval of 10 to ends of the woof yarns whileusing the ordinary warp yarns.

The electrically conductive fibers used in the invention include notonly those in which an electric resistance is in the region of anordinary conductor, but also those in which an electric resistance isvery high such as 2,000M0/cm. as in the case of forming a top coat layercomprising an organic polymer. It is surprising that a marked antistaticeffect is exhibited even when a small amount of a fiber having such highelectric resistance is incorporated. 'It is not easy to explain themechanism of prevention of electrification with simplicity. Generally, ahigh voltage above 1000 volts poses a problem in an unfavorableelectrification of ordinary organic textile fibers, and a quantity ofelectrostaticity generated at this time is very small. Hence, it ispresumed that even in the case of such high electric resistance, thelocal intrinsic electric breakdown of the coating occurs under such highvoltage, and the electrostatic charge is easily dispersed by sucheffects as gaseous corona discharge, surface flashover and tracking andleakage, thus preventing the accumulation of electrostatic charge. Thisseems to contribute greatly to the prevention of electrostatic charge.

The textile materials having durable antistatic properties can be of anyform, including staple blend, spun yarn, twisted yarn, string, cord,tape, woven, knitted or non-woven fabrics and carpets.

The following examples are given for further illustratron of thisinvention. The volume inherent resistivity values of the electricallyconductive textile material given in the examples are computed bymultiplying resistance values per unit length of the fiber measured witha universal bridge (Model BV-Z-13A) manufactured by Yokogawa ElectricWorks, Japan by the total cross-sectional area of the electricallyconductive fiber (including the substrate and metal coating), while theelectrification voltage values were measured by a collecting typepotentiometer (Model KS-325) manufactured by Kasuga Electric Company,Japan. The content of the electrically conductive textile material isshown in weight percent of the and its initial Youngs modulus is 100g./de. (computed in terms of the denier of the substrate filament, thevalues of the substrate filament were 3.6 g./de., 13% and 90 g./de.,respectively), and its retains practically the same pliability andflexibility as that of the substrate itself.

Carpets incorporated with this electrically conductive monofilament weremade by first mixing in this filament during the twisting step of Taslontreated nylon yarn (2600 total denier/136 filaments) and by incorporatedthe electrically conductive monofilament-incorporated nylon yarn at twoand five strand intervals (rate of mix 0.17 and 0.08%, respectively)during the tufting operation. The so made carpets were then scoured,dyed and applied a backing. When the so obtained tufted carpets wereused and the measurement of the electrification voltages was made byhaving a person walk thereover wearing leather-soled shoes and under theconditions of C. and 10% RH, the electrification voltages of the humanbody and carpets were as shown in the following table. It was thus seenthat the electrification voltages of the human body and carpet could bedecreased greatly by the incorporation of a very small amount of theelectrically conductive filament.

Content of Electrification voltage Electrification voltage electricallyof human body (volts) of carpet (volts) conductive filament NormalShufiling N ormal Shufiling Carpet (percent) walk walk walk walkElectrically conductive filament not incorporated 0 -5, 000 -13, 500 +6,000 +15, 000 Electrically conductive filament incorporated at 2 Strandintervals 0. 17 -l, 000 2, 000 +2, 000 +2, 600 Electrically conductivefilament incorporated at 5 strand intervals 0.08 -1, 000 -2, 000 +2, 000+2, 500

material contained based on the organic textile material, while thecomposition of the substrate organic synthetic fiber or filament isshown in mol percent.

EXAMPLE 1 A degreased 10 denier acrylic monofilament (a copolymericfiber containing 94.5% acrylonitrile, 4.5% methyl acrylate and 1% ofanother third component, wet spun by means of dimethylformamide) wascontinuously and successively immersed and passed through the followingbaths to deposit the chemical nickel plating.

(a) sensitizing bath (20 g./l. stannous chloride, 10 g./l. conc.hydrochloric acid) Room temperature 8 seconds. (b) Water-washing 'Roomtemperature '8 seconds.

(c) Activating bath (0.25 g./l. palladium chloride, 2.5 g./l. conc. hy-

drochloric acid) Room temperature '8 seconds. (d) Chemical nickelplating bath (predominantly 20 g./l. nickel sulfate, 24 g./l. sodiumhydrophosphite, 27 g./l. lactic acid; pH adjusted to 5.6) 88C., 80seconds. (e) Water-Washing Room temperature '8 seconds.

Thus, an electrically conductive filament having a nickel coating of anaverage thickness of 0.4 micron was obtained continuously. This filamenthas good conductivity, since its average volume resistivity is -1.0 l0'n-cm. Even after it was submitted to a test of its resistance tofriction [the filament is rubbed for 5 minutes under a load of 0.5-g./de., based on the substrate fiber, against a nylon gear (module3.61, number or teeth 40) rotating at 120 r.p.m.], there was practicallyno change in the resistance value, thus demonstrating the excellentadhesiveness of the nickel coating. The breakage strength of thisfilament is 3.6 g./de., its elongation at break is 14% In the case of anylon tufted carpet not incorporated with the electrically conductivefilament, a high voltage of static charge, as shown in the foregoingtable, was accumulated in the human body by walking in normal manner orin a shufliing manner. And in this case, an unpleasant severe shock isreceived in both cases when a metallic door knob is touched. On theother hand, in the case of the carpets incorporated with a small amountof the electrically conductive filament, in both cases theelectrification voltage of the human body is very low and no shock isreceived.

EXAMPLE 2 A degreased 200 total denier/ filaments acrylic multifilament(a copolymeric fiber containing 94.5% acrylonitrile, 4.5% methylacrylate and 1% of a third component, wet-spun by means of nitric acid)was used as the substrate, which was applied a chemical copper platingby being treated in sequence by the following baths; (a) an etching bath(75 g./l. chromic anhydride, 250 g./l. concentrated sulfuric acid),treatment for 15 seconds at room temperature; (b) water-washing bath;(c) sensitizing bath (a bath composition identical to that of Example1), treatment for 15 seconds at room temperature; (cl) waterwashingbath; (e) activation bath (a bath composition identical to that ofExample 1), treatment for 15 seconds at 50 C.; (f) water-washing bath;(g) chemical copper plating bath (a copper salt-formalin type chemicalplating bath consisting of 30 g./l. of copper sulfate, 100 g./l. ofRochelle salt and 50 ml./l. of formalin as principal components, andadjusted to a pH of 11-12 with sodium hydroxide), treatment for 6minutes at room temperature; and (h) water-washing bath. Thus wasobtained an electrically conductive filament excelling in flexibilityand pliability having a copper coating of average thickness of 0.062micron and an average volume inherent resistivity of. 2.9 10 item. Theconductivity of this filament changed hardly at all even when it wassubmitted to the test of its resistance to friction by means of a nylongear, as in Example 1. It is to be noted that in the case of a filamentapplied the chemical copper plating, the conductivity and adhesivenessare excellent even with a very thin plate thickness.

This electrically conductive filament was mixed with a degreased 24,200total denier/ 8300 filaments nylon'filament, in a prescribed amount, andthe filament was then electrified to saturation by rubbing on glass tubeunder the conditions of 20 C. and 40% RH. The filament was then heldabove the center of the metallic disk of a foil electroscope at a point1 cm. thereabove in a straight line and the angle of spread of theleaves was determined, with the results shown in the following table. Itis seen that a very excellent antistatic effect is demonstrated by theincorporation of only a small amount of the electrically conductivefilament.

. Rate of leaf Content of electrically conductive Leaf spread spread argle filament (percent) angle (degree) (percent) EXAMPLE 3 8 EXAMPLE 4Chemical nickel plating was applied to degreased 3 denier x. 76 mm.acrylic staples by operating as in Example 3, whereby were obtainedelectrically conductive staples having an average thickness of thenickel coating of 0.27 micron and an average volume inherent resistivityof 7.8x 10- Q-cm. A non-woven carpet was made by binding a web composedof 70% by weight of polyvinyl chloride staples and 30% by weight ofpolypropylene staples by the needle punch method and further binding theweb by spraying a bonding agent against the back. When this carpet wasvigorously rubbed by a person Wearing shoes under the conditions of 25C. and 12% RH, the human body and the carpet showed a charge of +6000and 8000 volts, respectively, and the severe shocks were felt by theperson when he touched a metal. However, in the case of a non-wovencarpet in which was dispersingly mixed in the web 0.3% of theelectrically conductive staples, obtained as hereinbefore described, theelectrification voltages of the human body and carpet were only +2000and 2000 volts, respectively, and no shock was felt by the human bodyupon touching a metal as in the foregoing instance. Thus, the antistaticeffect demonstrated was pronounced.

EXAMPLE 5 The electrically conductive filament applied with the chemicalnickel plating, as obtained in Example 1, was used as the cathode, andan electrolytic copper plating was also applied to the filament in anacid copper sulfate bath with a current density of 0.5 A./dm. Thus, anelectrically conductive filament having a further copper coat- Fiberproperties (calculated on the basis of the denier of the substratefilament) Average thickness Breakage Initial of nickel Breakage elon-Youngs coatin Average inherent restrenght gation modulus (micronsistivity (S2- cm.) (g./de.) (percent) (g.lde.)

Specimen No.:

1 0. 005 Discontinuity in the 3. 1 19 75 adhesion of metal. Nocouducitivity 0. 03 5 10- 3. 1 20 77 0. 4 1 1o- 3. 0 18 100 0. 9 4X10.2. 1 10 115 5 2. 0 2X10. 1. 0 1 210 Substrate filament 3. 1 78 When thefiber properties of the several electrically conductive filaments andthe properties of the substrate filament are compared, it is shown thatWhile the electrically conductive filaments of specimen Nos. 2, 3 and 4still retain their pliability and flexibility as organic textilematerials, the electrically conductive filament of specimen No. 5,having already lost its functional properties as an organic textilematerial, has been converted to one having the properties of a metallicwire.

When an electrification test was conducted as in Example 3, by mixingone strand of each of the electrically conductive multifilaments ofspecimen Nos. 2, 3 and 4 in a degreased 13,000 total denier/6220filaments acrylic filament and making the measurements using a, foilelectroscope, the results obtained were as follows. In all cases, apronounced antistatic eifect was demonstrated.

Content of electrically conductive Leaf spread Rate ofleal ing to anaverage thickness of 0.35 micron and an average volume inherentresistivity of 5.8 10- Sl-cm. was ob tained. A polyester plain fabricwas obtained. A polyester plan fabric was woven with this filamentincorporated at intervals of 1 cm. in the woof and warp directions(content 0.16% by weight). A 10 cm. x 10 cm. test piece, after scouringwas caused to be electrified to saturation by rubbing it with an acrylicfiber cloth at a speed of 6 cm. per second at 20 C. and 40% RH. When itselectrification voltage was measured 30 seconds later, it was only 420volts, as compared with 7300 volts in the case of the cloth notincorporated with the electrically conductive filament. It was thus seenthat this electrically conductive filament had a very excellentantistatic effect.

EXAMPLE 6 The filament obtained in Example 1 was dipped in nitrilerubber-phenol type bonding agent, then passed. through a slit to adjustits film thickness, dried and. hardened at C. to obtain a resin-coatedelectrically conductive filament having an average resin film thicknessof 0.3 micron and an average resistance value of ZOOOMQ/cm. [measured bythe automatic insulation resistance meter (Model L-68) mfg. by YokogawaElectric Works, Japan]. A nylon tufted carpet was made as in Example 1incorporating this filament as every other strand (content 0.26%). Whenthis was then measured Electrifica- Content tion voltage Specimen(percent) (volts) Not incorporated with electrically conductive filament2, 000 Incorporated with electncaly conductive filament not coated withresin 0.25 800 Incorporated with resin-coated electrically conductivefilament 0. 26 750 Further, when the hereinabove described carpet testpieces were measured for their electrification voltages after beingrotatingly rubbed by means of a jagged vinyl chloride resin frictionalelement (load 0.5 kg./cm. 23 rpm), the results were as shown in thefollowing table. The durability and resistance to abrasion were thusshown to be very excellent.

Electrification Friction applied: voltage (volt) Before abrasion 750After 500 rotations 850 After 1000 rotations 850 We claim:

1. A textile material having durable antistatic properties comprisingorganic textile fibers and electrically conductive fibers, characterizedin that said electrically conductive fibers are incorporated in saidorganic textile fibers in an amount of about 0.1-2% by weight of saidorganic textile fibers, and each of said electrically condnctive fiberscomprising a substrate of organic synthetic fibers made of an acrylicpolymer comprising at least 80 mol percent of acrylonitrile which hasbeen sensitized by adsorption of a reducing agent thereon, and then hasbeen activated by deposition of a noble metal thereon, and anclectrolessly plated metallic coating on said substrate, the averagethickness of said metallic coating being about 0.01-1.5 microns.

2. A textile material according to claim 1 wherein said electricallyconductive fiber comprises a substrate of organic synthetic fiber, anclectrolessly plated metallic coating thereon, and a top coating layerof organic polymeric material over said metallic coating to protect themetallic coating, said top coating layer being such that it does notcause the electric resistance of said fiber to exceed about 2000MSZ/cm.

3. A textile material according to claim 1 wherein said metallic coatingcomprises a metal selected from the group consisting of nickel andcopper.

4. A textile material according to claim 1 wherein said material is inthe form of staple blend, spun yarn, twisted yarn, string, cord, tape,woven fabric, knitted fabric, non-woven fabric or carpet.

5. A textile material according to claim 1 wherein said metallic coatingcomprises at least one metal selected from the group consisting ofnickel, copper, cobalt, chromium, zinc and tin.

6. A textile material according to claim 1 wherein the substrate fiberhas a finess of about 1 to denier.

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